reject mods which reference obsolete SGame class (#247)

src/StardewModdingAPI.AssemblyRewriters/Finders/GenericTypeFinder.cs

@@ -0,0 +1,30 @@
+using StardewModdingAPI.AssemblyRewriters.Framework;
+
+namespace StardewModdingAPI.AssemblyRewriters.Finders
+{
+    /// <summary>Base class for a type reference finder.</summary>
+    public class GenericTypeFinder : BaseTypeFinder
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A brief noun phrase indicating what the instruction finder matches.</summary>
+        public override string NounPhrase { get; }
+
+        /// <summary>The full type name to match.</summary>
+        public override string FullTypeName { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="fullTypeName">The full type name to match.</param>
+        /// <param name="nounPhrase">A brief noun phrase indicating what the instruction finder matches.</param>
+        public GenericTypeFinder(string fullTypeName, string nounPhrase)
+        {
+            this.FullTypeName = fullTypeName;
+            this.NounPhrase = nounPhrase;
+        }
+    }
+}

src/StardewModdingAPI.AssemblyRewriters/Framework/BaseTypeFinder.cs

@@ -0,0 +1,52 @@
+using System.Linq;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace StardewModdingAPI.AssemblyRewriters.Framework
+{
+    /// <summary>Base class for a type reference finder.</summary>
+    public abstract class BaseTypeFinder : IInstructionFinder
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A brief noun phrase indicating what the instruction finder matches.</summary>
+        public abstract string NounPhrase { get; }
+
+        /// <summary>The full type name to match.</summary>
+        public abstract string FullTypeName { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get whether a CIL instruction matches.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public virtual bool IsMatch(Instruction instruction, bool platformChanged)
+        {
+            string fullName = this.FullTypeName;
+
+            // field reference
+            if (instruction.OpCode == OpCodes.Ldfld || instruction.OpCode == OpCodes.Ldsfld || instruction.OpCode == OpCodes.Stfld || instruction.OpCode == OpCodes.Stsfld)
+            {
+                FieldReference field = (FieldReference)instruction.Operand;
+                return
+                    field.DeclaringType.FullName == fullName // field on target class
+                    || field.FieldType.FullName == fullName; // field value is target class
+            }
+
+            // method reference
+            if (instruction.OpCode == OpCodes.Call || instruction.OpCode == OpCodes.Callvirt)
+            {
+                MethodReference method = (MethodReference)instruction.Operand;
+                return
+                    method.DeclaringType.FullName == fullName // method on target class
+                    || method.ReturnType.FullName == fullName // method returns target class
+                    || method.Parameters.Any(p => p.ParameterType.FullName == fullName); // method parameters
+            }
+
+            return false;
+        }
+    }
+}

src/StardewModdingAPI.AssemblyRewriters/StardewModdingAPI.AssemblyRewriters.csproj

@@ -69,8 +69,10 @@
     <Compile Include="Finders\Game1_smoothFont_FieldFinder.cs" />
     <Compile Include="Finders\Game1_borderFont_FieldFinder.cs" />
     <Compile Include="Finders\SMAPI_Extensions_MethodFinder.cs" />
+    <Compile Include="Framework\BaseTypeFinder.cs" />
     <Compile Include="Framework\BaseFieldFinder.cs" />
     <Compile Include="Framework\BaseMethodFinder.cs" />
+    <Compile Include="Finders\GenericTypeFinder.cs" />
     <Compile Include="IInstructionRewriter.cs" />
     <Compile Include="IInstructionFinder.cs" />
     <Compile Include="Platform.cs" />

src/StardewModdingAPI/Constants.cs

@@ -146,7 +146,8 @@ namespace StardewModdingAPI
                 new Game1_smoothFont_FieldFinder(),
 
                 // APIs removed in SMAPI 1.9
-                new SMAPI_Extensions_MethodFinder()
+                new SMAPI_Extensions_MethodFinder(),
+                new GenericTypeFinder("StardewModdingAPI.Inheritance.SGame", "obsolete StardewModdingAPI.SGame class")
             };
         }